(a) Field of the Invention
This invention relates to an improvement of the ultrasonic air humidifying apparatus.
(B) Description of the Prior Art
Generally an ultrasonic air humidifying apparatus has a feature that the particles of the generated mist are very fine. However, depending on the state of the current of air delivering the mist, the already generated fine mist particles will conglomerate into large water drops and will return to a water vessel without being effectively delivered and not only the capacity of the apparatus will be reduced but also, if such means as of enlarging the cross-sectional area of a nozzle blowing out the mist is made to compensate the reduction of the capacity, large water particles will fly and disperse and the advantage of the ultrasonic air humidifying apparatus will be lost.
This state shall be explained with reference to an example of a conventional ultrasonic air humidifying apparatus whose basic arrangement is shown in FIG. 1. When an ultrasonic vibrator contained in a case C is excited by a high frequency generator not shown in the drawing, ultrasonic vibrations will be sent out toward the water surface which will be swollen to be in the form of a conical projection as shown by W and an ultrasonic energy will concentrate in an apex portion T of the conical projection W to mistify water. A wind blown out of a blower B will advance in the direction indicated by the arrow along the water surface, will flow into a conduit pipe P for delivering the mist, will rise carrying said mist and will be blown out of a nozzle N. However, in case the wind flowing along the water surface flows into the conduit pipe P for delivering the mist, due to its dynamic pressure, it will concentrate on the left side in the drawing, that is, on the side far from the blower B but, on the other hand, on the right side in the drawing, that is, on the side near to the blower B, a vacuum will be generated and air will reversely flow near the inlet of the conduit pipe and a vortex will wind as shown by the arrow in the drawing. In this part, the generated mist particles will be wound into the vortex and will collide with each other to conglomerate or will collide with the water surface to return into a water vessel V. On the side far from the blower B, as mentioned above, the wind velocity will be so high that even large water drops will be blown up and will be blown out of the nozzle N through the conduit pipe P. However, these large water drops will drop immediately by separating from the jet of the mist after having been blown out of the nozzle N. D shows that large water particles are separating and dropping. If the passage of the nozzle N is bent or is reduced in the cross-sectional area to remove large water particles, the amount of the mist will reduce by the amount lost in the above mentioned vortex. If the amount of the mist is not reduced, large particles will be contained.